okayy i'm bored. this morning went for band.. woke at 730 >< whoops. i should have been punished for lateness.. ahah. anyway, went down.. guess what two saxophones today.. gahh. and i sound terrible today for some reason. !! *stress* never even press the octave key then the bloody high notes come out. then end up looking stupid.. sigh. oh well.
bailed on going out after that.. came straight home. then.. gretch sam and charm and i, we all started convo.. gretch asked people to come along with her and jervo to watch over the hedge... (yes iddie, the movie is still GAYYY.. although i must say hammie is cute.)
ahh.. its so boring cant wait for thursday. then we all can go sentosa and muck around somemore =D anyways, now its.. 530 i'm damn bored. had a light chem session today.. HEAVY yesterday and trigo later :P why am i blogging down my lessons? oh ya cause i'm bored and getting mad in the head. i guess..
okay, here we go.
1) The chemical properties are determined by the number of electrons in the valence shell. (only for elements i think..)valence electrons = the group
2) Use Lewis diagram to represent molecule or compound formation. Use the octet rule and the silly steps as follows.
a) Choose central atom
b) Calculate total valence electrons
c) Give one bond to each pair of atoms
d) Excess goes to the terminal atom then the central atom
e) If octet rule not filled, or followed or whatever, increase number of bonds.
3) Energy for formation of ionic compounds. total energy for compound formation = energy for formation of ions + energies to form ionic compound.
4) Molecule shapes
a) linear - 180 degrees
b) Trigonal planar - 120 degrees
c) Tetrahedral - 109.5 degrees ??!! ><
d) Trigonal bipyramidal - 120 degrees for triangular base and 90 degrees for pyramid tip
e) Octahedral - all round 90
ya basically sounds like i'm crapping all this rubbish. oh well..
anyways, i can link you to a website on wikipedia about the lewis diagram. which my dad thinks might be .. important next sem.
yep..
posted by halfpastfour- at 5:14 PM [edit]
